Now in SW, I stick to increments of 5 for XP rewards but in our last System, the amount of XP for one session varied from 6 to 9 and the amount of XP you could do something with was sometimes as low as 2. Back then there was a possible point of XP per session for good RP per RAW. In the later periods, I tried something new by letting the players decide which character moments were their big favs this evening or who they thought just nailed it RP wise. The whole Table decided who gave them the best IC moment(s) and so the group allocated the bonus XP. I gave them around half the amount of Players in such bonus XP so they needed to decide together where to drop that XP (and no one could vote for themselves).
At my table, it worked out great it was a pure moment of recapping the most awesome stuff from that session and they surprised me more than once which actually were their favourites that session. It also turned out to give me more insight into what kind of interactions they overall preferred and could try to put more like those into the plot to have more awesome moments to choose from.
The other big benefit was shifting the Bonus-RP-XP from a possibly biased GM viewpoint (we sometimes don't see everything and possibly tend to favour some kind of interactions over others) over to what gave the whole table the most fun that evening.
Such methods could, in my opinion, counter some (if not all) of the maybe "being punished" bitterness when it comes to individual bonus XP. At the time I used it for different reasons but I think it can work that way also.
You can't win this one buddy.